The buildup to the comment that drew the audience's ire came after Colbert asked him if, as one of the senior leaders in the Republican Party, he could explain what the heck is happening with the GOP.

“This is one of the most unusual times in political history,” McCain responded. “There’s a great deal of anger, there’s a great deal of unhappiness, one of the weakest recoveries in history, millions of people have stopped looking for jobs, and there’s a great antagonism towards Washington.”

McCain then reprised one of the two jokes he’s told again and again over the last few years: “I landed at LaGuardia Airport today, and some guy came up to me and said, ‘Has anyone ever told you you look like John McCain?’

"Yeah," I said.

"'Doesn’t that make you mad as heck?’”

Colbert, ever the diplomat, let him get away with it.

And he let him get away with telling the other joke about sleeping like a baby after the losing the presidential election against Barack Obama.

“There’s an anger out there so we get what we have,” McCain went on to say. “But I would remind you this time four years ago that the leader in the polls for the Republican nomination was Herman Cain, and then it was followed by Michele Bachmann.”

“And how have you felt about the Bachmann-Cain administration?” Colbert snapped back.

“Hey, come on over to John McCain’s BBQ,” he said. “[He’ll tell you] your kid’s ugly.”

Colbert then turned the conversation to a more serious subject: the Iran deal. He mentioned having Secretary of State John Kerry on the show the previous week and how Kerry framed the issue as a choice between the nuclear deal or war with Iran.

“Do you believe it was that dire?” Colbert asked McCain, one of the most outspoken critics of the deal.

“No, I believe that if we had a better deal, then it could have been something we could work with.”

Colbert did not let him off the hook: “Well, what would that deal have looked like? Because just sanctions led to more centrifuges and getting closer to a bomb.”

“It would have had much better verification and inspection procedures. It would not have released $100 billion — do you know what the Iranians are going to do with $100 billion? They’re the ones that keep chanting ‘Death to Israel, death to America.”

McCain then added that, right now, Iran is also bolstering it’s support for the Assad regime in Syria.

Colbert responded by asking if the United States should have boots on the ground in ISIS-controlled areas of Iraq and Syria?

McCain, a big fan of the thumb's up hand signal.

Screenshot/YouTube

“I think we should definitely have boots on the ground — not a lot, but we better do something.”

“Can you give me an idea of how many troops you’re talking about?” Colbert asked.

“I’m talking a couple thousand.”

“Just a couple thousand? We couldn’t bring order to Iraq with a hundred thousand troops in 10 years.”

Over the audience's applause, it was almost impossible to hear McCain say: “We did bring order to Iraq."

“But the moment we left, it all disappeared,” Colbert fired back.

“Exactly, and all of us predicted that would happen,” McCain said, looking out at the audience as if he expected them to cheer in agreement.

“What concerns me, and I think other people,” Colbert said, “is it sounds like [you’re saying], ‘Put that amount of troops in there and then leave them there indefinitely.’ Will we end up being a peacekeeper there for forever and a day?”

McCain said no, and smiling slyly, mentioned that the U.S. has had troops in South Korea for 38 years.

Before Colbert had a chance to comment, McCain launched into why “America is the greatest nation in the world.”

The segment ended with Colbert asking McCain if he’s going to run for president again in 2016.

McCain’s response: “A famous Southern philosopher once said, ‘There’s no education in the second kick of a mule.’ So no.”